
One of the problems you'll face when developing for a mobile phone is "Highscores".
Any dynamic string of text in general is hard on a mobile device, as you never know if your fonttype is supported or how it's actually going to look on the final device.
The answer is to use your own generated bitmap font, and have MMF generate a bitmap every time you need a dynamic string. It takes a bit of looping and time to import all the characters you need, but it's very possible and the advantage is that you get to control exactly how your text appears on the device.
I've uploaded an example taken directly from my own game. I'm not a great programmer but it works, and I'm sure other would like to see how it could be done. You guys might even be able to optimize the code!
http://www.burfelt.com/java/highscore/Mobile_highscores.zip